This can vary, some shapes have different area formulas, here are some basic formulas I can give you:
Circle: A =


Triangle: A =

Square: A =

Rectangle: A = L*W
Simply plug in numbers!! (3x-1)(5)=55
15x-5=55
15x=60
x=4
hope this helps :)
Answer:
<h2>u = 0</h2>
Step-by-step explanation:

Probably the last one
Use the equation for the area of a triangle 1/2(bxh)
Then multiply that number by 2 to get the area of the complete shape.
Answer:
its 10
Step-by-step explanation:
You have to put them from least to most and see the middle number.